There is an emerging consensus that individual health outcomes are a result of multiple factors that range from biological to societal and that the proper understanding and quantification of the etiologic roles of genes and environments in the causation of diseases will require consideration of gene by environment interactions. However, traditional approaches to understanding the causes of individual health outcomes remain fragmented into biological and social approaches. Just as this paradigm often falls short in adequately explaining the causes for individual health outcomes, it also fails to adequately explain disparities in health outcomes at the population level. Despite the repeated documentation of racial and ethnic disparities in hypertension and obesity there is still substantial debate about their root causes. Identifying the range of factors that lead to the persistent and pronounced differences in the blood pressures and/or body mass index (BMI) of populations is critical for developing effective strategies for reducing these disparities. The Health Retirement Study (HRS) is a key cohort in which to conduct research at the intersection of the biological and social since it is a nationally- representative longitudinal panel study of oer 26,000 adults over age 50 (surveyed every two years). The rich combination of the blood pressure and BMI measures along with genomic data in the HRS presents an important opportunity to investigate the contribution of genetic, socioeconomic, and psychosocial factors to blood pressure and BMI in a large cohort study to accomplish the following specific aims: Aim 1: Estimate molecular-based heritability of blood pressure and body mass index (BMI) in a multi-ethnic cohort of nearly 16,000 older adults from the Health and Retirement Study. Aim 2: Investigate the gene-level and SNP-level associations of 60 gene regions that have significant and replicated evidence of association with blood pressure and BMI. Aim 3: Investigate socioeconomic status and psychosocial factors as modifiers of the molecular-based heritability, gene-level associations, and SNP-level associations with blood pressure and BMI.